The invention relates to a travelling-wave tube wherein a delay line on which RF is imposed and which is in the form of a helix is positioned between an electron beam generator and a target.
Travelling-wave tubes comprising a helix-like delay line accommodated within a vacuum envelope are known, for example, from the German Letters Pat. No. 19 37 704, corresponding to U.S. Pat. No. 3,634,723, incorporated herein by reference. Given these travelling-wave tubes, a plurality of mounting rods of dielectric material which have good thermal contact to the vacuum envelope are disposed parallel to one another along generated lines of the delay line.
It is likewise already known to manufacture the vacuum envelope and the delay line of copper and to solder these parts to the mounting rods which is formed of dielectric material, for example beryllium oxide (German Letters Pat. No. 28 38 515, incorporated herein by reference).
It is further known to allow the vacuum envelope which has first been expanded by means of heating to shrink onto the mounting rods (German Letters Pat. No. 19 37 704, incorporated herein by reference).